Control module



April 14, 1970 J. MCARTHUR comm. MODULE Fiied Jan. 5, 1967 INVENYUR ZEsTER J. M flnmun u/1MM1MM g lyzziw l/fome y s United States Patent Office 3,506,882 Patented Apr. 14, 1970 3,506,882 CONTROL MODULE Lester J. McArthur, Wabash, Ind., assignor to Wabash Magnetics, Inc., Wabash, Ind., a corporation of Indiana Filed Jan. 3, 1967, Ser. No. 606,681

Int. Cl. H01h 47/04, 47/12 US. Cl. 317--137 9 Claims ABSTRACT OF THE DISCLOSURE A control module having two relays, each relay having contacts operated by a coil that is provided with a blocking diode, a bypass diode and a series resistor.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to electric circuits for relays and electromagnets and more particularly to pulse responsive relays for information storage and sequential operation.

Description of the prior art Many circuits for providing relay logic and memory functions have been devised and are known in the art. Some of them, for example those shown in Werst 3,042,900 and Tevonian 3,088,056, require relay coils having three windings. Others, such as shown by Keller 3,118,090, employ remanent magnetic material and multiple winding coils. Still others, such as described in Jacobson 3,020,369 and Deeg 3,244,942 require a complex physical arrangement of coils, contacts and magnetic shunt material.

Some of the above-cited devices find application in special circumstances. The Keller device, for example, may be particularly suited to applications where power consumption must be kept to an absolute minimum, but its cost and complexity tend to make it unsuitable for many general applications. This is generally true of all the devices requiring multiple winding coils, the cost of multiple winding coils being somewhat higher than the cost of single winding coils. Where extremely high speed operation is required, solid state or semiconductor circuits are generally dictated, their operating speeds exceeding that of mechanical contacts by several magnitudes. The solid state circuits, however, are generally not capable of handling power in excess of a few hundred miliwatts, or a few watts at the most. Additionally, the solid state devices generally require rather expensive power supply devices.

There exists a need for a control module adaptable to perform a large number of logic and memory functions and which is simple in construction and economical to manufacture. It should provide comparatively high operating speeds and yet be capable of handling comparatively large power, while not requiring the expensive power supply devices necessary for solid state devices.

SUMMARY OF THE INVENTION The present invention is an improved relay control module for providing logic and memory functions.

It may include two relays with single-winding coils. The coil of each relay is connected in series with a blocking diode and a voltage-dropping resistor, and the blocking diode and coil are connected in parallel with a bypass diode. A latching circuit is provided from a source of latching potential through a normally open contact of the first relay to both relay coils at a point between each coil and its respective blocking diode.

Application of a pulse at one point in the circuit will cause the first coil to be energized and operate its contacts while the second coil is prevented from being ener-.

gized by the action of the diodes for the duration of the pulse. When the pulse is terminated, the second coil is energized by current from the latching circuit which also maintains energization of the first coil. When the second coil is energized, its contacts are operated from the normal to the operated position.

Application of a pulse at another point in the circuit will simultaneously de-energize the first coil and maintain energization of the second coil, thereby opening the latching circuit but not operating the second relay contacts during the duration of the pulse. When the pulse is terminated, the second coil is de-energized, and its contacts return to the normal position.

As will be described in more detail subsequently, the module of the present invention provides a bistable electrical circuit for providing logic and memory functions. Each relay may be provided with a plurality of normally open and normally closed contacts which are electrically isolated from the above-described circuit and are available to operate other circuits and to interconnect the module with other identical or similar modules to form various counters, shift registers, and storage units. For example, interconnection of these contacts may adapt the modules to function as a single input flip-flop circuit as a not circuit, as an or circuit or as an and circuit. In other words, the present invention provides a basic building block which may be interconnected with other circuitry by well known and conventional techniques to provide any desired logic function. The control module of this invention has a comparatively high operating speed and is capable of handling comparatively large powers. It utilizes single-winding relay coils which are simpler and more economical to manufacture than relays having multiple winding coils.

It is therefore an object of this invention to provide an improved control module.

It is a further object of this invention to provide a module of simple construction that is economical to manufacture.

It is yet another object of this invention to provide a module having comparatively high operating speeds and which is capable of handling a comparatively large amount of power.

These and other objects will become apparent as the description proceeds, reference being made to the drawings, description of the preferred embodiment, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic diagram of the circuit of the present invention.

FIG. 2 is a front elevational view, partly in section, of the module of the present invention.

FIG. 3 is an enlarged sectional view of an encapsulated switch forming a part of the structure of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more specifically to FIG. 3, there is generally illustrated the type of switch used in the preferred embodiment of the present module. An encapsulated switch 11 is located so that it lies within the influence of a magnetic field created by passing electrical current through the coil 12. The encapsulated switch may be of any of the well known wet or dry contact types. In the switch 11 there are two electrically conductive reeds 13 formed of paramagnetic material having a comparatively low residual magnetism and are sealed in and supported by the nonconductive and nonmagnetic envelope 14, which is generally evacuated. The reeds 13 are normally spaced apart from each other in overlapping .relationship as shown in FIG. 3. When the switch 11 is subjected to a magnetic field generally parallel to the reeds 13, such as a field generated by the coil 12, the field tends to be concentrated within the reeds, and induces magnetic poles at the extremities of the reeds 13. In a magnetic field of either polarity, and of a certain magnitude, opposite magnetic poles will be induced in the overlapping ends of the reeds 13 causing them to attract each other and move into engagement, thereby completing the electrical circuit from the terminal 16 to the terminal17.

It is well known in the art that the contacts of the encapsulated switch may be held in engagement by a smaller field than is required to move them into engagement, and it is also well known how to bias the contacts with permanent magnets of such strength that the contacts will operate either as normally closed contacts or as self-latching bistable contacts. Any of these techniques may be used with the present module without departing from the spirit of the invention or the intended scope of the claims.

Referring now to FIG. 1, there are two winding means in the form of single-winding coils 21 and 22. The first coil 21 controls first contact means in the form of switches 21a, 21b, 21c, 21d and 21a. It should be mentioned that FIG. 2 for simplicity shows only three switches 21a, 21b and 210 and, of course, any greater or lesser number can be used. The second coil 22 controls second contact means in the form of switches 22a, 22b, 22c and 22d. One end of each of the coils 21 and 22 is connected to a source of reference potential, such as ground, through resistors 23 and 24 respectively. The other ends of the coils 21 and 22 are connected together, to one side of diodes 26 and 27, and to one side of the switch 21a. The other side of diode 26 is connected to the terminal 31 and to one side of the diode 28, which has its other side connected between the coil 21 and the resistor 23. The other side of diode 27 is connected to the terminal 32 and to one side of the diode 29, which has its other side connected between the coil 22 and the resistor 24. The other side of the switch 21a is connected to a source of latching potential (not shown) through the terminal 33.

The operation of the control module 20 is controlled by pulses introduced at the terminals 31 and 32, as will be described in more detail subsequently. The orientation of the diodes 26, 27, 28 and 29 shown in FIG. 1 is for the use of positive going pulses, as indicated by the waveform representations adjacent the terminals 31 and 32. Should the use of negative going pulses be desired, a reversal of each of the diodes 26, 27, 28 and 29 would be required. Of course, the polarity of the source of latching potential must be the same as the polarity of the pulses used and the polarity of any biasing magnets would have to be changed.

The control module 20 may easily be mounted on a circuit board 34 as shown in FIG. 2, or any other of a large number of possible physical mountings which are well known in the art. The permanent magnet 30 biases the switches 22b and 220 to act as normally closed switches.

The control module 20, as shown in the preferred embodiment, is adapted to provide what is commonly known as four-step logic. That is, four distinguishable changes or steps are required to return the module to any given state. Two of these states are stable and are switches 21a, 21b, 21c, 21d, 21c, 22a and 22d are open,

and switches 22b and 22c are closed.

To shift the module to the set state, a positive pulse is applied to terminal 32, which causes current to flow through diodes 29 and 27. The current flowing through diode 29 flows through junction 41 and through the resistor 24 to the source of reference potential. Because of the low forward resistance of diode 29, there is very little voltage drop across it, and therefore substantially all of the voltage drop from terminal 32 to the reference. potential appears across the resistor 24 making the potential at junction 41 substantially equal to the potential of terminal 32. Substantially all of the current flowing through diode 27 flows through junction 42, coil 21 and resistor 23 to the source of reference potential. Substantially no current will flow through coil 22 because both of its ends (junctions 41 and 42) are at substantially the same potential. Also, no current will flow through the diodes 26 or 28 because of their high backward resistance. The current flowing through coil 21 operates the switches 21a, 21b, 21c, 21d and 21e, changing them from the open to the closed position. Closure of the switch 21a completes the latching circuit which connects coils 21 and 22 to the source of latching potential. For the remainder of the pulse at terminal 32 substantially no current will flow through the diode 27 because the resistance of switch 21a is lower than the forward resistance of diode 27. This assumes, of course, that the. source of latching potential is equal to or greater in amplitude than the pulse at terminal 32. The module is now in the transitional state referred to as the setting state.

When the pulse applied to terminal 32 ends, any current flowing from terminal 32 ceases to flow and all current flows through the latching circuit. The latching current maintains the energization of coil 21 and energizes coil 22. Because each of the diodes 26, 27, 28 and 29 are now biased in the reverse direction by the latching potential, substantially no current will flow through them. The latching switch 21a remains in the closed position because the coil 21 is continued energized. The switches 22a and 22d close and the switches 22b and 220 open because the coil 22 is energized. The module is now in the set state.

To shift the module from the set state to the reset state, a pulse is applied at terminal 31. This will cause current to flow in the forward direction through diode 28, the junction 43, and the resistor 23 to the source of reference potential. Because the forward resistance of the diode 28 is much lower than the resistance of the resistor 23, substantially all of the voltage drop from the terminal 31 to the source of reference potential is across the resistor 23, making the potential of the junction 43 substantially equal to the potential of the junction 44 which is at latching potential. This makes both ends of coil 21 at substantially the same potential, and causes current to cease flowing in coil 21. When this happens, switches 21a, 21b, 21c, 21d and 21e open. The opening of switch 21a opens the latching circuit, tending to lower the potential of the junction 44. As the potential of the junction 44 tends to fall, current begins to flow in the forward direction through the diode 26 from the terminal 31 and acts to hold up the potential of the junction 44. This current flows through the coil 22 maintaining it in an energized condition. The module is now in the second transitional state referred to as the resetting state.

When the pulse applied to the terminal 31 ends, any current flowing from terminal 31 ceases to flow. No potential difference then exists across either of the coils 21 or 22, therefore the switches 21a, 21b, 21c, 21d and 21e remain in the open position, the switches 22a and 22d move from the closed to the open position, and the switches 22b and 22c move from the open position to the closed position. The module is now once again in the reset state.

In certain applications, for example ring counters, it may be desirable to prime the control module so that it is in the set state before certain pulses are applied to it. To this end a priming terminal 46 may be connected to the module at a point common to the junctions 42 and 44. Application of a positive pulse at the terminal 46 directly energizes the coils 21 and 22, which energization is then maintained by the latching circuit, holding the module inthe set state until such time as a pulse is applied to terminal 31 or the latching current is otherwise interrupted.

Although the present invention has been described with reference to a particular illustrative embodiment, it should be understood that numerous modifications and embodiments thereof can be devised by those skilled in the art that will fall within the spirit of the present invention and within the scope of the claims. For example, if it is desired that the shift from resetto set be-produced by the leading rather than the trailing edge of a pulse applied to terminal 32, the diode 29 may be. removed or otherwise open circuited. Similarly, if it is desired that the shift from set to reset be produced by the. leading rather than the trailing edge of a pulse applied to terminal 31, the diode 26 may be removed or otherwise open circuited.

The invention claimed is:

1. A control module comprising;

first contact means operable between first and second positions;

first winding means providing a magnetic field for operating said first contact means; I first circuit means connected to said first winding means for energizing said first winding means to operate said first contact means to said second position; second circuit means connected to said first winding means for energizing said first winding means;

said second circuit means including said first contact means;

third circuit means connected to said first winding means for de-energizing said first winding means to operate said first contact means to said first position;

said first, second and third circuit means including a first resistance connected between said first winding means and a source of reference potential;

said first circuit means including a first asymmetrical conducting device having one end connected to said first winding means and said third circuit means including a second asymmetrical conducting device having one end connected to said first winding means and to said first resistance.

2. A control module comprising:

first contact means operable between first and second positions;

first winding means providing a magnetic field for operating said first contact means;

first circuit means connected to said first winding means for energizing said first winding means to operate said first contact means to said second position; second circuit means connected to said first winding means for energizing said firstwinding means;

said second circuit means including said first contact means;

third circuit means connected to said first Winding means for de-energizing said first winding means to operate said first contact mearis to said first position;

said first, second and third circuit means including a first resistance connected between said first winding means and a source of referefice potential;

second contact means operable between first and second positions;

second winding means providing a magnetic field for operating said second contact means;

said second circuit means being connected to said second winding means for energizing said second winding means;

said first circuit means including a first asymetrical conducting device having one end connected to said first winding means and to said second winding means, said third circuit means including a second asymmetrical conducting device having one end connected to said first winding means and to said first resistance.

3. A control module comprising:

first contact means operable between first and second positions;

first winding means providing a magnetic field for operating said first contact means;

first circuit means connectedto said first winding means for energizing said first winding means to operate said first contact means to said second position; second circuit means connected to said firstj winding means for energizing said first winding means;

said second circuit means including said first contact means;

third circuit means connected to said first winding means for de-energizing said first winding means to operate said first contact means to said first position;

said first, second and third circuit means including a first resistance connected between said first winding means and a source of reference potential;

second contact means operable between first and second positions;

second winding means providing a magnetic field for operating said second contact means;

saidsecond circuit means being connected to said second. winding means for energizing said second winding means;

said first and second circuit means including a second resistance connected between said second winding means and said source of reference potential.

4. The control module of claim 3 wherein said first circuit means includes a first asymmetrical conducting device having one end connected to said first winding means and to said second winding means, and said third circuit means includes a second asymmetrical conducting device having one end connected to said first winding means and to said first resistance.

5. The control module of claim 4 wherein said first circuit means includes a third asymmetrical conducting device having one end connected to said secondwinding means and to said second resistance, and having the other end connected to the other end of said first asymmetrical conducting device.

6. The control module of claim 4 wherein said third circuit means includes a fourth asymmetrical conducting device having one end connected to said first-winding means and to said second winding means, and having the other end connected to the other end of said second asymmetrical conducting device.

7. The control module of claim 4 wherein said first circuit means includes a third asymmetrical conducting device having one end connected to said second winding means and to said second resistance, havingthe other end connected to the other end of said first asymmetrical conducting device, and said third circuit means includes a fourth asymmetrical conducting device having ,one end connected to said first winding means and to said second windingrneans, and having the other end connected to the other end of said second asymmetrical conducting device.

8. The control module of claim 7 further comprising fourth circuit means connected to said first winding means and to said second winding means for energizing said first and second winding means to operate said first and second contact means to said second positions.

9. A control module comprising first contact means, first winding means providing a flux field for opening and closing the first contact means, second contact means, second winding means providing a flux field for opening and closing the second contact means, first circuit means connected to the first and second winding means for energizing the second winding means to operate the second contact means, second circuit means connected to the first and second winding means for energizing the first circuit means to operate the first contact means, third circuit means connected to the first and second winding means for energizing both of said winding means to operate both of the first and second contact means, said first circuit means including a first and a second asymmetrical conducting device and a resistance, said first asymmetrical conducting device being connected in series with said first winding means, said second asymmetrical conducting device being connected in parallel with said first winding means and said first asymmetrical conducting device, said resistance being connected in series with said asymmetrical 8 7 References Cited UNITED STATES PATENTS 3,244,942 4/1966 Deeg 317137 3,389,308 6/1968 Jones 317-140 X JAMES D. TRAMMELL, Primary Examiner US. Cl. X.R. 

